Metrology requirements for the integrated luminosity measurement using small angle Bhabha scattering at ILC

Precision measurement of the integrated luminosity $\mathcal{L}$ at future Higgs factories, including ILC, is of crucial importance for the cross-section measurements, and in particular for the line-shape measurements at the Z-pole. Since there is no up-to-date estimate of the integrated luminosity uncertainties arising from metrology effects at ILC, here we review the metrology requirements for the targeted precision of $\mathcal{L}$ at foreseen ILC center-of-mass energies: 91.2 GeV, 250 GeV, 500 GeV and 1 TeV, using small-angle Bhabha scattering.